A.T. Robertson Commentary Revelation 19:14

"And the armies which are in heaven followed him upon white horses, clothed in fine linen, white [and] pure." — Revelation 19:14 (ASV)

The armies which are in heaven (τα στρατευματα τα εν τω ουρανω). See 12:7 for Michael and angels warring with the dragon, and also Mt 26:53 for the angels at Christ's call, not to say Heb 1:6f.,14; Matthew 13:41; Revelation 5:11f.

Followed (ηκολουθε). Imperfect active and singular (στρατευματα, neuter plural) of ακολουθεω, graphic picture of the celestial Warrior with his angelic hosts "upon white horses" (εφ' ιπποις λευκοις) like the Leader and, like him "clothed in fine linen white and pure" (ενδεδυμενο βυσσινον λευκον καθαρον) like the Leader again (19:8). Note ενδεδυμενο here as in 1:13; 15:6.